Clinical Performance of the Standard Q COVID-19 Rapid Antigen Test and Simulation of its Real-World Application in Korea

Ann Lab Med. 2021 Nov 1;41(6):588-592. doi: 10.3343/alm.2021.41.6.588.

Abstract

The rapid antigen test (RAT) for coronavirus disease (COVID-19) represents a potent diagnostic method in situations of limited molecular testing resources. However, considerable performance variance has been reported with the RAT. We evaluated the clinical performance of Standard Q COVID-19 RAT (SQ-RAT; SD Biosensor, Suwon, Korea), the first RAT approved by the Korean Ministry of Food and Drug Safety. In total, 680 nasopharyngeal swabs previously tested using real-time reverse-transcription PCR (rRT-PCR) were retested using SQ-RAT. The clinical sensitivity of SQ-RAT relative to that of rRT-PCR was 28.7% for all specimens and was 81.4% for specimens with RNA-dependent RNA polymerase gene (RdRp) threshold cycle (Ct) values ≤23.37, which is the limit of detection of SQ-RAT. The specificity was 100%. The clinical sensitivity of SQ-RAT for COVID-19 diagnosis was assessed based on the Ct distribution at diagnosis of 33,294 COVID-19 cases in Korea extracted from the laboratory surveillance system of Korean Society for Laboratory Medicine. The clinical sensitivity of SQ-RAT for COVID-19 diagnosis in the Korean population was 41.8%. Considering the molecular testing capacity in Korea, use of the RAT for COVID-19 diagnosis appears to be limited.

Keywords: Coronavirus disease; Korea; Laboratory surveillance; Rapid antigen test; Real-time reverse-transcription PCR.

Publication types

  • Evaluation Study

MeSH terms

  • COVID-19 / diagnosis*
  • COVID-19 / virology
  • COVID-19 Testing / methods
  • Humans
  • Nasopharynx / virology
  • RNA, Viral / analysis
  • RNA, Viral / metabolism
  • RNA-Dependent RNA Polymerase / genetics*
  • Real-Time Polymerase Chain Reaction
  • Republic of Korea
  • SARS-CoV-2 / genetics*
  • SARS-CoV-2 / isolation & purification

Substances

  • RNA, Viral
  • RNA-Dependent RNA Polymerase